I In nt tr ro od du uc ct ti io on n: : Spinal fusion with instrumentation is an essential component in the management of degenerative condition in the spinal motion segment. It is performed to improve initial stability with simplified external fixation for early ambulation1)2). The solid fixation, however, often induces an adjacent segment degeneration (ASD) above or below the fusion 3). ASD c...

STUDY DESIGN A study using an anatomically accurate finite-element model of a L2-L3 motion segment to investigate the biomechanical effects of graded bilateral and unilateral facetectomies of L3 under flexion and extension loadings. OBJECTIVE To predict the amount of facetectomy on lumbar motion segment that would cause segmental instability, therefore enhancing the understanding concerning t...

In this paper, we present a motion compensated two-link chain coding technique to e ectively encode 2-D binary shape sequences for object-based video coding. This technique consists of a contour motion estimation and compensation algorithm and a two-link chain coding algorithm. The object contour is de ned on a 6-connected contour lattice for a smoother contour representation. The contour in th...

Cheng et al 1 have discussed using a dynamic posterior stabilization device to treat asymmetric collapse of an artificial disc in the coronal plane. Although this may correct the radiographic coronal-plane abnormality, there are significant biomechanical considerations to be kept in mind. When using these 2 devices in conjunction with each other at the same motion segment, the degrees of freedo...

OBJECTIVE To compare the clinical outcomes and biomechanical effects of total disc replacement (TDR) and posterior cervical foraminotomy (PCF) and to propose relative inclusion criteria. METHODS Thirty-five patients who underwent surgery between 2006 and 2008 were included. All patients had single-level disease and only radiculopathy. The overall sagittal balance and angle and height of a fun...

BACKGROUND The optimal technique to intubate the trachea in patients presenting with a potential or documented cervical spine (C-spine) injury remains unresolved. Using continuous fluoroscopic video assessment, C-spine motion during laryngoscopy with an AirTraq Laryngoscope (King Medical Systems, Newark, DE) was compared to that with intubation using a Macintosh blade. METHODS Twenty-four hea...

This study investigates the relative effect of soft tissue properties on the overall response of a human spinal motion segment using an osseo-ligamentous FE model of the Visible Man L3-L4 intervertebral joint. Model geometry was obtained from the Visible Man CT dataset using custom built image processing software. Non-linear soft tissue properties were obtained from the literature. Displacement...

In this paper, we present a motion compensated twolink chain coding technique to effectively encode 2-D binary shape sequences for object-based video coding. This technique consists of a contour motion estimation and compensation algorithm and a two-link chain coding algorithm. The object contour is defined on a 6-connected contour lattice for a smoother contour representation. The contour in t...

BACKGROUND Anterior lumbar disc replacements are used to restore spinal alignment and kinematics of a degenerated segment. Compared to fusion of the segment, disc replacements may prevent adjacent segment degeneration. To resolve some of the deficiencies of anterior lumbar arthroplasty, such as the approach itself, difficulty of revision, and postoperative facet pain, 360° motion preservation s...

BACKGROUND Biomechanical investigations of spinal motion preserving implants help in the understanding of their in vivo behavior. In this study, we hypothesized that the lumbar spine with implanted total spinal segment replacement (TSSR) would exhibit decreased dynamic stiffness and more rapid energy absorption compared to native functional spinal units under simulated physiologic motion when t...